On the planet Tenebrae in The Zuran Expanse there exists three city-sized labyrinths comprised of basalt-like material zealously guarded by squat humanoids called “skulkers.” Their origins unknown, skulkers are utterly hostile to other sophonts and pose a near-constant danger to explorers and scavengers of the labyrinth. They appear to live adjacent to the labyrinth but whether they make their homes in ancient support structures or warrens they dug themselves is uncertain.